Antenna feed systems which produce two orthogonally polarized signals are known. When the antenna system's direction of radiation must be changed, it is necessary to adjust the position of the polarization plane. One device used to change the polarization plane is a rotary joint. Although such joints have been used in communications satellites, particularly in direct radiation communications satellites, they are not trouble-free. It is difficult to make such joints pressure-proof, high frequency-proof and tolerant of high breakdown field strengths. When these qualities have been met, the resulting joints have been mechanically complicated and heavy, which qualities are very undesirable for space-based equipment.
It is an object of this invention to provide a device for rotating and adjusting the polarization plane of an antenna feed system which avoids the aforesaid disadvantages of a rotary joint, has good electrical properties, and can be used in direct radiation communications satellites.